Cm871 randomly shuts down

[Brett389]

I have a 389 with a cm871 has been deleted for 8 years. A few months ago I was loaded going down the hwy and it shuts off like you turned the key off, I pulled over checked for loose wires and bad connections found nothing so I changed the fuel shut off seloniod that didn’t help but I was able to get unloaded even tho it shut off a few times more and was able to get home. It’s totally at random so I’m thinking it’s a electrical ghost and l started to throw parts at it so I changed the key switch and got lucky that was 4 months ago and thought I solved the problem it didn’t shut off not one time until yesterday and doing the exact same thing. I searched the internet and found one guy that had exact engine with exact problem and a new ecm solved his problem

[alamow]

I experienced a simular issue with random shutdowns. Borrowed a ECM and problem solved.

I've read on this forum that tapping the ECM with a screwdriver/hammer can be used as a diagnostic tool.

You may find this post interesting https://rawze.com/forums/showthread.php?tid=5025

[tree98]

Yep, probably the ECM. Now is your opportunity to put a safe demandate program in the new ECM because I'll bet you have a bad engine destroying program in it now. Who did the demandate do you remember?

[Brett389]

I sent it to some guy in Indiana that was 8-9 years ago

[Brett389]

I’m thinking ecm to but recon why the new key switch got 4 more months out of it

[tree98]

(09-10-2022 )Brett389 Wrote:  I’m thinking ecm to but recon why the new key switch got 4 more months out of it

Probably just coincidence??

[Rawze]

here ya go...
http://rawze.com/forums/showthread.php?t...3#pid70893

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And yeah,.. you need to copy the program out of the ecm ans have it properly reviewed to ensure it is not harmful to the engine. Does not matter how well you think it has been running so far.

[Brett389]

Well I tried it this morning with a new key switch and it went 5 miles, so I’m headed to get a new ecm

[tree98]

Did you check the things mentioned in the thread Rawze linked above?